Warm Up

http://www.phschool.com/atschool/academy123/html/bbapplet_wl-problem-431621.html

This only works with right triangles! 3.8 HL Postulate Postulate: If there exists a correspondence between the vertices of two right triangles such that the hypotenuse and a leg of one triangle are congruent to the corresponding parts of the other triangle, the two right triangles are congruent. HL This only works with right triangles!

Then triangle ABC = Triangle ADC SSS 1 B 2 D 3 4 C Given: AB = AD <1 = <2 Thus <3 = <4 So BC = CD, AC = AC Then triangle ABC = Triangle ADC SSS

A B D C C Leg, right angle, hypotenuse, S A S

Given circle O YO ⊥ YX ZO ⊥ ZX Conclude: YX = ZX Y O X Z Statement Reason Circle O Given OY = OZ Radii of circle are congruent (L) OX = OX Reflexive (H) <OYX = <OZX ⊥ ⇒ right < (<) △OYX = △OZX HL (2, 3, 4) YX = ZX CPCTC

Remember, you still have three things to prove congruent: Right angle One leg Hypotenuse

http://www. classzone. com/books/geometry_concepts/page_build2. cfm http://www.classzone.com/books/geometry_concepts/page_build2.cfm?id=game&ch=5&CFID=40580573&CFTOKEN=83522164